Vermiculite is a super water absorbent growing medium which evenly distributes water using capillary action! You can think of vermiculite as being the gardening version of a sponge. Vermiculite is a naturally occurring mineral which expands when heated to high temperatures - forming layered and absorbent strands. Some of its main features are:
Great at absorbing nutrients
Evenly distributes water
Good drainage capabilities
Using vermiculite in hydroponic growing
Vermiculite is a staple hydroponic growing medium due to it's great water and nutrient retention properties. Vermiculite can be used in wicking bed systems, or as the growing medium in net cups for NFT systems.
Using vermiculite for indoor plants
Some indoor plants are thirsty and thrive off moist soil. You can mix vermiculite with soil in a 70/30 (soil/vermiculite) ratio to increase water retention and soil moisture. You can adjust the ratio depending on how much moisture your plants need, if they need high moisture levels then a 50/50 mix may be more appropriate.
Using vermiculite in propagations
Plant cuttings can be placed directly in moist vermiculite and left to grow. It's a great way to propagate plants as it allows more root aeration, than you would get if you were to simply put the cuttings in water. Furthermore, it's harder for the plant stems to rot as they sometimes do in water.
Using vermiculite in seed sowing
Seeds of all sizes can be growing in vermiculite. Simply fill a container that has drainage holes in it with vermiculite, soak your vermiculite in water, sprinkle seeds over the top of the growing medium. For larger seeds (bigger than a grain of rice), cover them in a light layer (1cm) of vermiculite. Once the seedlings emerge, expose them to sunlight or one of our LED grow lights.
That's everything on vermiculite. If you wan't to learn more, check out the rest of our series: